There are two elevator banks in Police Headquarters – one is restricted to top brass, the other for everyone else.

That’s why jaws dropped the other afternoon when Police Commissioner Bernard Kerik boarded an elevator filled with cops and civilian employees who toil in One Police Plaza rather than take the private elevator, which requires a special access card to get in.

“It’s OK,” Kerik quipped. “This is my building, and I can ride any elevator I want.”

The commissioner’s brief and cordial elevator ride from the rarefied atmosphere of his 14th floor office typifies a genuine openness he has brought to traditionally stuffy Police Headquarters, NYPD observers say.

Kerik’s affable style – jacket off as he walks the hallways and schmoozes staffers – has even captured public attention as he visits local churches and community groups.

And he’s received so much positive press coverage for making two arrests – as well as for playing Santa to a Brooklyn grandmother – he recently passed up making another collar and waited for local patrol cops to arrive.

Kerik’s demeanor – including his ease in front of reporters – is a marked change from his predecessor Howard Safir and other former commissioners.

Safir, a former federal drug-enforcement agent and top official in the U.S. Marshal Service, was viewed as a classic “fed” – less collegial, aloof and traveling with an entourage of security.

Former commissioner Lee Brown, who became a fed after leaving the NYPD, was equally stiff. Brown served as the nation’s drug czar before being elected mayor of Houston.

“I have to admit, Kerik is like a breath of fresh air around here,” said one top police official who also worked with – and had a “very good relationship” with – Safir.

The NYPD also suffered two of its biggest black eyes on Safir’s watch: the Abner Louima station-house torture case and the police killing of Amadou Diallo.

People close to Kerik are quick to point out that Kerik’s warmer-and-fuzzier temperament, however, does not mean he lacks the kind of steely crime-fighting personality to continue the winning war on murderers, rapists and thieves. Kerik holds a black belt, was a detective involved in near-death shootings and served as city correction commissioner to over 14,000 inmates.

While winning points for accessibility and friendliness, Kerik’s been tough, too. He ousted a well-regarded longtime NYPD budget director who was not moving quickly enough for Kerik, and shook up commands where crime was spiking upward.

Dennis Walcott, president of the New York Urban League, recalled meeting Kerik his first day as commissioner.

“He called me on his first day on the job, introduced himself, and we met on his second day. We had a frank discussion around issues that were important on bridging the gap with the community.”

Walcott said the meeting ended with him extending an invitation for Kerik to attend a football game sponsored by his organization. Although Kerik’s own son had a game that day, the commissioner showed up. “He wanted to keep his word and, to me, it earned a tremendous respect,” Walcott said.

“I found him to be direct and no-nonsense,” Walcott continued. And the operative word for him is sincere. Even if you disagree, he is direct in responding. He makes connections with people.”

As for Safir, Walcott said he attended lots of community meetings but never did much to publicize it, thus reinforcing his image as aloof.

Safir also attracted negative publicity with his penchant for the high life. The city Conflicts of Interest Board slapped him for taking a free trip to Hollywood for the Oscars from a Revlon exec in 1999. Safir quietly repaid the $7,100 cost before the board’s report was released.

“Kerik is different in that he is more comfortable going without the normal entourage around him. He seems like the type who is more comfortable going directly into the ‘hood and not having any qualms about it.”

“People see him responding directly and with a serious style, and that goes a long way to building trust.

Kerik is trying the same tactic on his cops to rebuild morale – Kerik visits precincts, spots eyesores and immediately orders repairs to be made. And there is hell to pay if there is any unexplainable delay. Just ask his former budget director.